Banca de DEFESA: RAFAEL CASSADOR MONTEIRO
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.DISCENTE : RAFAEL CASSADOR MONTEIRO
DATA : 20/02/2020
HORA: 13:00
LOCAL: Sala Marcelo Nunes Camargo, n°24, Departamento de Solos
TÍTULO:
Effect of the introduction of Arachis pintoi cv. Belomonte in pastures of Brachiaria brizantha cv. Marandú on dairy production and nitrogen dynamics
PALAVRAS-CHAVES:
BNF, GHGs, Forage legumes, pasture, Brachiaria
PÁGINAS: 115
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
RESUMO:
The greenhouse effect is an essential natural process for life on earth. However, the concentration of the gases responsible for global warming has been increasing in the atmosphere. Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) are among the most important greenhouse gases (GHG). Agriculture is the main Brazilian economic activity, however, it is the main producer of N2O, therefore, it is one of the sectors targeted for the implementation of GHG emission mitigation measures. Some of the mitigating measures for agriculture undertaken by Brazil in the Low Carbon Agriculture Plan are the recovery of degraded areas and increased biological nitrogen fixation (BNF). The recovery of degraded areas involves the use of mineral fertilizers that increase GHG emissions after being added to the soil, as well as transport and application stages, which also emit GHGs. The objective of this study was to compare the N cycle between braquiária brizantha Cv Marandú pastures fertilized with 120 kg N ha-1 year-1 (Bb + N) and intercropped with forage peanut Cv Belmonte (Bb + Ar). An experiment was installed at the Far South Experimental Station (ESSUL) of the Executive Committee of the Cacao Plantation (CEPLAC) in Itabela - BA. The adopted system was rotated with 6 days of grazing and 30 days of rest, with three repetitions. Throughout the project, milk production and quality, N2O and NH3 emissions from fertilizer and excreta, urinary and fecal production of animals, as well as N-content of excreta, as well as consumption and intake of N and legume was calculated, and N recycling from litter. N2O fluxes from each treatment were performed using closed static chambers. The first monitoring was started in July 2018 with the application of urea and excreta, and was terminated in January 2019, the following month a new application took place and was conducted until September 2019. Milk production varied over the period. Due to climatic seasonality, which directly influences the amount and quality of forage available to animals, the average production in the period was approximately 517 kg milk ha-1 for Bb + Ar, while Bb + N production was 480 kg milk ha-1. In the first application losses due to fertilizer NH3+ volatilization amounted to 1.38 kg N ha-1, which represented 1.87% of the applied urea, in the second application losses were 2.09 kg N ha-1, 2,49% of the applied urea. In the first application, losses via N2O emission represented 1.69%. The introduction of legumes in the system increased background emissions from intercropping pastures. In excreta, fecal emissions were low, however, for urine, high N2O emission occurred in the first days after application. The decomposition rate of the litter was similar between treatments and was affected with the animals entering the paddocks, the average rates were 0.092 and 0.088 g g-1 day-1, Bb + Ar and Bb + N, respectively. With the animals leaving, in the first 6 days of rest, the rates were 0.100 and 0.104 g g-1 day-1 Bb + Ar and Bb + N, respectively, with increasing rest time the decomposition rate was reduced to approximately 0.060 g g-1 day-1 in both treatments.
MEMBROS DA BANCA:
Presidente - 644.889.777-15 - ROBERT MICHAEL BODDEY - OUTRO
Interno - 1104775 - ADELSON PAULO DE ARAUJO
Interna - 1740899 - ERIKA FLAVIA MACHADO PINHEIRO
Externo à Instituição - OCTAVIO COSTA DE OLIVEIRA - IBGE
Externo à Instituição - DAVID VILAS BOAS DE CAMPOS - EMBRAPA